| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [to-vb] [conj] [det] [is] | 316 |
|
| 2 | difficult [to-vb] [conj] [det] | 74 |
|
| 3 | difficult [to-vb] [conj] [is] | 8 |
|
